The issuance of leveraged loans-the fuel driving the engines of corporate mergers, buyouts and debt refinancings-has declined significantly so far this year as deal-making continues at a sluggish pace and regulatory scrutiny over leverage levels intensifies, according to S&P Capital IQ LCD.

This year through Aug. 31, companies issued $310.1 billion in leveraged loans, down from $398.4 billion for the same period in 2014, LCD’s data show.